A CODING APPROACH FOR DETECTION OF TAMPERING IN WRITE-ONCE OPTICAL DISKS

We present coding methods for protecting against tampering of write-on ce optical disks, which turns them into a secure digital medium for ap plications where critical information must be stored in a way that pre vents or allows detection of an attempt at falsification. Our method i nvolves adding a small amount of redundancy to a modulated sector of d ata. This extra redundancy is not used for normal operation, hut can b e used for determining, say, as a testimony in court, that a disk has not been tampered with.